Is this information in the manual somewhere?
I believe you since a watt is a watt and the charger shouldn't have any trouble converting the AC power coming in to DC for the batteries if it has enough power, but....the specs I find on-line seem to indicate that the 120V charging rate is always much lower than the 240V rate. This document http://nissannews.com/media_storage/dow ... -FINAL.pdf
which comes from what would seem to be an 'official' site shows the 120V rate to be about half the 240V rate for both the 3.3kW and 6.6kW chargers. In fact, looking at this, the only advantage of the upgraded charger option is the DC quick charger port since it shows the L2 charge times to be about equal between the 3.3kW and 6.6kW (6.0 kW ?) on-board chargers.
Edit to add: A lot of my questions are answered here in older posts: '3.3 kW' charger means car can accept 3.3kW but draw 3.8kW while '6.6kW charger' means car can draw 6.6kW but accepts only 6.0kW, hence the naming confusion, or here https://insideevs.com/charging-levels-explained-bower/
Interesting that L1, L2, or L3 can be either AC or DC. That was news to me.